High demands are placed on the visual display and processing in medical applications in order to be able to represent large medical images and/or image data. Although the final display is comparatively small, large source data is processed and immediate image results are expected. In the medical field, a so-called client server architecture prevails for the processing, display and storage of medical images. This means that large image data is frequently transferred to and fro between the users, i.e. a client computer, and a server, i.e. a central unit. If adjustments are to be made to the image characteristics on the client side, image data is frequently called up from the server in the direction of the client and vice versa, which is costly in terms of time and resources.